Piezoelectric accelerometers may be made using various components and geometries. Some piezoelectric accelerometers use piezoelectric sensing elements mounted to an elastic membrane. Piezoelectric transducers are used to sense a mechanical deformation of the elastic membrane and generate an electrical signal indicative of the mechanical deformation. Piezoelectric transducers can produce a voltage, a current, or a charge in response to changes in pressure, acceleration, temperature, strain, or force, etc. Such transducers can be used to monitor processes or deformable members. Some piezoelectric transducers are configured to generate an electric signal only in response to accelerations in a specific direction.
Piezoelectric accelerometers may have a proofmass attached to an elastic membrane. The elastic membrane is configured to span from the proofmass to a device to be acceleration tested. When the device under test is accelerated, inertia of the proofmass will cause the proofmass to move in a dissimilar fashion than the movement of the accelerating device under test. Because of this dissimilar movement, the elastic membrane spanning between the proofmass and the device under test, may distort. This distortion may be sensed by the piezoelectric transducer and converted into an electric signal indicative of such a distortion.
Accelerometers may be axially asymmetric, even for devices intended to sense only or primarily axial accelerations. For example, an axially-thin elastic membrane may laterally extend from a first axial end of the proofmass. A second axial end of the proofmass may project away from the axially-thin elastic member. A lateral force acting upon the accelerometer can cause the proofmass to become canted with respect to the axially-thin elastic membrane, to which it is attached. Such canting of the proofmass can cause the axially-thin elastic membrane to deform. Such a deformation may be detected by a piezoelectric transducer mounted on the axially-thin elastic membrane, thereby causing a signal indicative of acceleration, albeit a lateral acceleration. In some applications, suppressing lateral accelerations may improve the signal-to-noise ration of axial acceleration measurements.